Composites and composite membranes

ABSTRACT

The invention relates to a composite or a composite membrane consisting of an ionomer and of an inorganic optionally functionalized phyllosilicate. The isomer can be: (a) a cation exchange polymer; (b) an anion exchange polymer; (c) a polymer containing both anion exchanger groupings as well as cation exchanger groupings on the polymer chain; or (d) a blend consisting of (a) and (b), whereby the mixture ratio can range from 100% (a) to 100% (b). The blend can be ionically and even covalently cross-linked. The inorganic constituents can be selected from the group consisting of phyllosilicates or tectosilicates.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/603,017, filed Oct. 21, 2009, now U.S. Pat. No. 8,110,517, which is acontinuation of the U.S. National Phase of International Application No.PCT/EP00/03910, filed May 2, 2000, now published as WO 00/74827, whichclaims priority to German Patent Application No. DE 199 19 881.0, filedApr. 30, 1999, the entire disclosure of each of which is herebyincorporated by express reference hereto.

FIELD OF THE INVENTION

The present invention involves providing composites which possess a highion conductivity (especially proton conductivity) and simultaneouslylimited swelling ability and permit an operating temperature inelectrochemical cells of above 100° C. The invention relates thus to anion conducting composite containing an acid and/or an organic base and aphyllosilicate, wherein the composition of the acid-base part is presentin an amount from 1 to 99 weight % and the phyllosilicate is present inan amount from 99 to 1 weight %.

BACKGROUND OF THE INVENTION

Ionomer membranes are used in many processes, for example, in membranefuel cells, in electrodialysis, in diffusion dialysis, in electrolysis(PEM electrolysis, chlorine alkali electrolysis), or in electrochemicalprocesses.

A disadvantage of the actual membranes is, however, that their protonconductivity at temperatures above 100° C. in most cases decreasesrapidly due to drying up of membranes. Temperatures above 100° C. are,however, very interesting for fuel cell applications of ionomermembranes, because above 100° C. the temperature regulation of fuelcells is greatly simplified and the catalysis of the fuel cell reactionis substantially improved (excess voltage decreased, no CO-loading anymore, which poisons the catalyst).

Only a few examples of membranes which still exhibit good protonconductivity even above 100° C. are known from the literature, forexample poly(phenylene)s havingcarbonyl-1,4-phenylene-oxyphenyl-4-sulfonic acid side groups. Howeverthe proton conductivity of these membranes decreases rapidly above 130°C., and the reason for the good proton conductivity between 100° C. and130° C. is also not clear.

Proton conductivity is based on the Grotthus mechanism with protons inacidic media and hydroxyl ions in alkaline media acting as chargecarriers. There exists a structure crosslinked via hydrogen bondsenabling the actual charge transport. That means the water contained inthe membrane plays an important part in the charge transport: withoutthis additional water, there is no mentionable charge transport acrossthe membrane in these commercially available membranes; they lose theirfunction. Other new developments, which use phosphate backbones insteadof a fluorohydrocarbon backbone, also need water as an additionalnetwork builder. (Alberti et al., SSPC9, Bled, Slowenia, 17.-21.8.1998,Extended Abstracts, p. 235). While the addition of small SiO₂ particlesto the above mentioned membranes (Antonucci et al., SSPC9, Bled,Slowenia, 17.-21.8.1998, Extended Abstracts, p. 187) leads to astabilization of proton conductivity up to 140° C., this only appliesunder operating conditions of a pressure of 4.5 bar. Without increasedoperating pressure, these membranes also lose their water network above100° C. and dry up. A substantial disadvantage of all the abovementioned membrane types is therefore that, even under best operatingconditions, they are usable at application temperatures of up to 100° C.

In the same manner as mentioned above, Denton et al. (U.S. Pat. No.6,042,958) prepared composites from ion conducting polymers and poroussubstrates. As silica containing components, they used glass, ceramics,or silica. In the examples described therein, the operating temperaturewas not increased above 80° C.

While in the direct methanol fuel cell (DMFC) sufficient water ispresent, methanol crossover through the membrane, however, results in asubstantial decrease of power.

If composites of sulfonated polyaryletheretherketone membranes (EuropeanPatent No. EP 0574791 B1) or sulfonated polyethersulfone and silica areprepared, the membrane swells at an cation-exchange capacity of 1.5meq/g to an extent that it is ultimately destroyed.

Phyllosilicates (clay minerals) have some interesting properties:

-   -   They can bind hydrate water up to 250° C.    -   In these materials, metal cations and metal oxides can be        additionally incorporated, inducing hereby an intrinsic proton        conductivity according to the general scheme:        M^(n+)(H₂O)→(M-OH)^((n−1)+)+H⁺    -   [Zeolite, Clay and Heteropoly Acid in Organic Reactions, Y.        Izumi, K. Urabe, M. Onaka; 1992; Weinheim, VCH-Verlag, p. 26].    -   Phyllosilicates having Lewis acid cavities may intercalate by        acid-base interaction with the basic groups of basic polymers    -   [Kunststoffnanokomposite, symposium: Von der Invention zur        Innovation, Publication at the Symposium of the Fonds of the        Chemical Industry, 6^(th) of May, 1998, in Cologne].

Due to these properties, some types of phyllosilicate/polymer compositeshave been synthesized. Mühlhaupt et al. made composites frommontmorillonite and polypropylene, montmorillonite and polyamide, andmontmorillonite and PERSPEX™. In these composites, for example, thePERSPEX becomes hardly flammable, due to the admixture withmontmorillonite, because the incorporated phyllosilicates are barriersto the pyrolysis gases formed on combustion.

DESCRIPTION OF THE FIGURE

FIG. 1 is a depiction of three (3) embodiments of the invention.

SUMMARY OF THE INVENTION

The advantage of the composites according to the invention, and themembranes prepared therewith, is the incorporation of an organiccomponent, especially of protonated nitrogen bases, into the cavities ofthe phyllosilicates, which is a cross-linking component, when the baseis provided on a polymer backbone. Furthermore, the selectiveincorporation of cations or metal hydroxides with subsequent reaction tothe corresponding metal oxides permits varying the Lewis acid propertiesand size of the membrane cavities in a wide range. Moreover, thephyllosilicates can be functionalized to interact with ionomers in whichthey are embedded or to influence the surrounding medium according totheir functional group.

The invention relates to an ion conducting composite comprising: (A) apolymer; (B) an acid-base component comprising an acid and/or a base;and (C) a phyllosilicate and/or tectosilicate, wherein components (A)and (B) can be combined into a polymer comprising an acidic and/or basicgroup. The sum of the amounts of the acid-base component and the polymerare from 1 to 99 weight % and the amount of phyllosilicate and/ortectosilicate is from 99 to 1 weight %. The acid and/or a base ispresent in the cavities of the phyllosilicate and/or tectosilicate.

In one embodiment, an ionomer is used as the combination of components(A) and (B) and is selected from the group consisting of

-   (a) a cation exchange polymer comprising a cation exchange group    —SO₃H, —COOH, and/or —PO₃H₂, wherein the polymer can be    non-cross-linked or covalently crosslinked and the polymer backbone    can be a vinyl polymer, an aryl main chain polymer, polythiazole,    polypyrazole, polypyrrole, polyaniline, polythiophene or any blend    of these;-   (b) an anion exchange polymer comprising an anion exchange group    —NR₃ ⁺, PyrH⁺, ImR⁺, PyrazR⁺, TriR⁺, and/or other organic basic    aromatic and/or non-aromatic groups, wherein R is a hydrogen, alkyl,    or aryl group, wherein the polymer is non-cross-linked or covalently    crosslinked, and wherein the polymer comprises a vinyl polymer, an    aryl main chain polymer, polythiazole, polypyrazole, polypyrrole,    polyaniline, polythiophene, or a blend thereof;-   (c) a polymer containing on the polymer chain both anion exchange    groups from (b) and cation exchange groups from (a), wherein the    polymer comprises a vinyl polymer, an aryl main chain polymer,    polythiazole, polypyrazole, polypyrrole, polyaniline, polythiophene,    or a blend thereof; or-   (d) a blend of (a) and (b), wherein the mixing ratio can range from    100% of (a) to 100% of (b), wherein the blend is covalently and    ionically cross-linked, and wherein the polymer comprises a vinyl    polymer, an aryl main chain polymer, polythiazole, polypyrazole,    polypyrrole, polyaniline, polythiophene, or a blend thereof.

Preferably, the ionomer is an ionomer blend (d), and the phyllosilicateis montmorillonite or clinoptilolite.

In another embodiment, a precursor of the ionomer is used as thecombination of components (A) and (B) and is selected from the groupconsisting of

-   (a) the precursor of a cation exchange polymer (a1) comprising    COHal, CONR₂, or COOR groups; a cation exchange polymer (a2)    comprising SO₂Hal, SO₂NR₂, or SO₂OR groups; or a cation exchange    polymer (a3) comprising PO₃Hal₂, PO₃NR₂)₂, or PO₃(OR)₂ groups,    wherein R is a hydrogen, alkyl, or aryl group, and wherein Hal is a    fluorine, chlorine, bromine, or iodine atom; or-   (b) the precursor of an anion exchange polymer comprising —NR₂,    pyridyl, imidazolyl, pyrazolyl, triazolyl, and/or other organic    basic aromatic and/or non-aromatic groups, wherein R is a hydrogen,    alkyl, or aryl group, and wherein Hal is a fluorine, chlorine,    bromine, or iodine atom.

Advantageously, the phyllosilicate is a bentonite. More preferably, thebentonite is montmorillonite. Alternatively, the phyllosilicate may be apillared phyllosilicate, and/or the tectosilicate may be a zeolite, suchas clinoptilolite.

In one embodiment, the basic component contains imidazole,vinylimidazole, pyrrazole, oxazole, carbazole, indole, isoindole,dihydrooxazole, isooxazole, thiazole, benzothiazole, isothiazole,benzoimidazole, imidazolidine, indazole, 4,5-dihydropyrazole,1,2,3-oxadiazole, furazane, 1,2,3-thiadiazole, 1,2,4-thiadiazole,1,2,3-benzotriazole, 1,2,4-triazole, tetrazole, pyrrole, aniline,pyrrolidine, or pyrrazole groups.

In one embodiment, the polymer component (A) comprises an acid polymer,and wherein the backbone of the polymer comprises one or more of thefollowing repeat units:

R_(aromatic) R_(bridge)

If the polymer component (A) is a basic polymer, the backbone of thepolymer may comprise one or more of the repeat units above or one ormore of the following repeat units:

Components (A) and (B) may be combined into 1) a polymer comprising anacidic group and 2) a polymer comprising a basic group.

The composite is useful as a component in a fuel cell which operates attemperatures from −40° C. to 200° C., or a reverse osmosis or(electro)membrane separator which separates two or more gases or liquidswith a membrane comprising the composite. The composite is also usefulas a component in a catalytic membrane or a membrane reactor.Advantageously, the composite exhibits thermal resistance up to 400° C.

The invention also contemplates a process for the preparation of thecomposite, wherein the polymer component, the acid-base component, andthe phyllosilicate and/or tectosilicate component are brought intocontact, optionally with a solvent, at a temperature from −40° C. to300° C.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(a) The acid may be a cation exchange polymer (having cation exchangegroups —SO₃H, —COOH, —PO₃H₂, wherein the polymer can be modified withonly one of the described cation exchange groups or with a blend of thedescribed cation exchange groups); wherein the polymer can be notcross-linked or covalently cross-linked. The ion exchange capacity ingeneral is comprised between 0.1 and 12 meq/g, more preferably between0.3 and 8 meq/g, most preferably between 0.5 and 2 meq/g. Particularlypreferred as backbone are thermoplastics.

(b) The acid can also be an organic or inorganic low molecular weightacid. In the inorganic acid case, sulfuric and phosphoric acid areparticularly preferred. In the organic acid case, all low molecularweight acids that are sulfonic or carboxylic acids are taken intoconsideration, especially all amino sulfonic acids and theaminosulfochlorides as their precursors.

(c) The base may be an anion-exchange polymer (having anion exchangegroups —NR₃ ⁺(R═H, alkyl, aryl), pyridinium (PyrR⁺), imidazolium ImR⁺),pyrazolium (PyrazR⁺), triazolium (TriR⁺), and other organic basicaromatic and/or non-aromatic groups (R═H, alkyl, aryl), wherein thepolymer can be modified with only one of the described anion exchangegroups or with a blend of the described anion exchange groups); andwherein the polymer can be non-cross-linked or covalently cross-linked.The anion exchange capacity herein is preferably between 1 and 15 meq/g,more preferably between 3 and 12 meq/g, most preferably between 6 and 10meq/g. Preferred as backbone are again all thermoplastics, particularlypolysulfone, polyetheretherketone, polybenzimidazole, andpolyvinylpyridine.

(d) The base can be an organic or inorganic low molecular weight base.As an organic low molecular weight base, all guanidine derivatives areparticularly preferred.

(e) The functional group of the acid and the base may be in the samemolecule. This molecule can be low or high molecular weight. If it is apolymer, then on the polymer chain there are anion exchange groups from(c) as well as cation exchange groups from (a).

(f) The above-mentioned acids and bases of (a) to (e) may be blended inthe composite. Any mixing ratio can be chosen. The blend can be furthercovalently cross-linked, in addition to the ionic cross-linking.

(g) If both the acid and the base are low molecular weight, there is inaddition an unmodified polymer contained in the composite.

(h) The inorganic active filler is a phyllosilicate based onmontmorillonite, smectite, illite, sepiolite, palygorskite, muscovite,allevardite, amesite, hectorite, talc, fluorhectorite, saponite,beidelite, nontronite, stevensite, bentonite, mica, vermiculite,fluorvermiculite, halloysite, fluor containing synthetical talc types,or blends of two or more of the above-mentioned phyllosilicates. Thephyllosilicate can be delaminated or pillared. Particularly preferred ismontmorillonite.

The weight ratio of the phyllosilicate is preferably from 1 to 80%, morepreferably from 2 to 30% by weight, most preferably from 5 to 20%.

The term “a phyllosilicate” in general means a silicate, in which theSiO₄ tetraeders are connected in two-dimensional infinite networks. (Theempirical formula for the anion is (Si₂O₅ ²⁻)_(n)). The single layersare linked to one another by the cations positioned between them, whichare usually Na, K, Mg, Al, or/and Ca, in the naturally occurringphyllosilicates.

By the term “a delaminated functionalized phyllosilicate,” we understandphyllosilicates in which the layer distances are at first increased byreaction with so-called functionalisation agents. The layer thickness ofsuch silicates before delamination is preferably 5 to 100 angstroms,more preferably 5 to 50, and most preferably 8 to 20 angstroms. Toincrease the layer distances (hydrophobization), the phyllosilicates arereacted (before production of the composites according to the invention)with so-called functionalizing hydrophobization agents, which are oftenalso called onium ions or onium salts.

The cations of the phyllosilicates are replaced by organicfunctionalizing hydrophobization agents, whereby the desired layerdistances which depend on the kind of the respective functionalizingmolecule or polymer which is to be incorporated into the phyllosilicatecan be adjusted by the kind of the organic residue.

The exchange of the metal ions can be complete or partial. Preferred isthe complete exchange of metal ions. The quantity of exchangeable metalions is usually expressed as milli equivalent (meq) per 1 g ofphyllosilicate and is referred to as ion exchange capacity. Preferredare phyllosilicates having a cation exchange capacity of at least 0.5,preferably 0.8 to 1.3 meg/g.

Suitable organic functionalizing hydrophobization agents are derivedfrom oxonium, ammonium, phosphonium, and sulfonium ions, which may carryone or more organic residues.

As suitable functionalizing hydrophobization agents, those of generalformula I and/or II are mentioned:

where the substituents have the following meaning:

R₁, R₂, R₃, and R₄ are independently from each other: hydrogen, astraight chain, branched, saturated or unsaturated hydrocarbon radicalwith 1 to 40, preferably 1 to 20, C atoms, optionally carrying at leastone functional group, or 2 of the radicals are linked with each other,preferably to a heterocyclic residue having 5 to 10 C atoms, morepreferably having one or more N atoms,

X represents phosphorous or nitrogen,

Y represents oxygen or sulfur,

n is an integer from 1 to 5, preferably 1 to 3, and

Z is an anion.

Suitable functional groups are hydroxyl, nitro, or sulfo groups, whereascarboxyl or sulfonic acid groups are especially preferred. In the sameway, sulfochloride and carboxylic acid chloride groups are especiallypreferred.

Suitable anions, Z, are derived from proton delivering acids, inparticular mineral acids, wherein halogens, such as chlorine, bromine,fluorine, iodine, sulfate, sulfonate, phosphate, phosphonate, phosphite,and carboxylate, especially acetate, are preferred. The phyllosilicatesused as starting materials are generally reacted as a suspension. Thepreferred suspending agent is water, optionally mixed with alcohols,especially lower alcohols having 1 to 3 carbon atoms. If thefunctionalizing hydrophobization agent is not water-soluble, then asolvent is preferred in which said agent is soluble. In such cases, thisis especially an aprotic solvent. Further examples for suspending agentsare ketones and hydrocarbons. Usually, a suspending agent miscible withwater is preferred. On addition of the hydrophobizing agent to thephyllosilicate, ion exchange occurs, whereby the phyllosilicate usuallyprecipitates from the solution. The metal salt resulting as a by-productof the ion exchange is preferably water-soluble, so that thehydrophobized phyllosilicate can be separated as a crystalline solid,for example, by filtration.

The ion exchange is mostly independent from the reaction temperature.The temperature is preferably above the crystallization point of themedium and below the boiling point thereof. For aqueous systems, thetemperature is between 0 and 100° C., preferably between 40 and 80° C.

For a cation and anion exchange polymer, alkylammonium ions arepreferred, in particular if, as a functional group, additionally acarboxylic acid chloride or sulfonic acid chloride is present in thesame molecule. The alkylammonium ions can be obtained via usualmethylation reagents, such as methyl iodide. Suitable ammonium ions areomega-aminocarboxylic acids; especially preferred areomega-aminosulfonic acids and omegaalkylaminosulfonic acids.Omega-aminosulfonic acids and omega-alkylaminosulfonic acids can beobtained with usual mineral acids, for example, hydrochloric acid,sulfuric acid, or phosphoric acid, or by methylation reagents, such asmethyl iodide.

Additional preferred ammonium ions are pyridine and laurylammonium ions.After hydrophobizing, the layer distance of the phyllosilicates is ingeneral between 10 and 50 angstroms, preferably between 13 and 40angstroms.

The hydrophobized and functionalized phyllosilicate is freed of water bydrying. In general, a thus treated phyllosilicate still contains aresidual water content of 0-5 weight % of water. Subsequently, thehydrophobized phyllosilicate can be mixed in form of a suspension in asuspending agent, which is free as much as possible from water with thementioned polymers and can be further processed. According to theinvention, the polymers, especially preferably the thermoplasticfunctionalized polymers (ionomers), are added to the suspension of thehydrophobized phyllosilicates. This can be done using already dissolvedpolymers, or the polymers are dissolved in the suspension itself.Preferably, the ratio of the phyllosilicates is between 1 and 70 weight%, more preferably between 2 and 40 weight %, and most preferablybetween 5 and 15 weight %.

Process for Producing the Composite

The present invention concerns, furthermore, a process for producingcomposite membranes. In the following, process examples to produceproton conducting composites having high proton conductivity aredescribed.

1) An aminoarylsulfochloride is dissolved in tetrahydrofuran. Then, acorresponding quantity of montmorillonite K10 is added. Themontmorillonite is proton exchanged and dried. Then, stirring forseveral hours follows. The time of stirring depends on the molecularsize of the aminoarylsulfochloride and the ratio of the amino group tothe cation exchange capacity of the montmorillonite. During the stirringprocess, the amino group intercalates into the cavities of themontmorillonite. To the suspension, sulfochlorinated polysulfonedissolved in tetrahydrofuran is then added. The sulfochloride content ofthe thermoplastic is approximately 0.5 groups per repeating unit. Thesuspension is stirred, gently degassed and knife-coated into a film on aglass plate. The tetrahydrofuran is evaporated at room temperature. Thecontent of montmorillonite is chosen to be between 5 and 10 weight % ofthe added sulfochlorinated polysulfone. Once the film is totally dried,the film is peeled off in deionised water and cured in 10% hydrochloricacid at 90° C. Hereby, the sulfochloride groups are hydrolyzed andreacted to sulfonic acid groups. The resulting membrane is additionallycured in water of 80-90° C., until hydrochloric acid is no longerdetectable.

A sulfochlorinated polysulfone having 0.5 SO₂Cl groups per repeatingunit corresponds, after hydrolysis, to a cation exchange capacity of 1.0milliequivalent per gram. Due to the additional sulfonic acid groupsfrom the aminoarylsulfochloride, the cation exchange capacity increasesremarkably, corresponding to the quantity thereof, and is notwater-soluble. At the same cation exchange capacity, exclusivelysulfonated polysulfone is water-soluble.

2) Sulfonated polyetheretherketone, having a cation exchange capacity(IEC) of 0.9 milliequivalent per gram, is dissolved in hot (T>80° C.)N-methylpyrrolidone (NMP). The sulfochlorinated form having such acontent is not soluble in THF. Polymeric sulfonic acids and their saltsare not, or only to a very small extent, soluble in THF. To thissolution, a suspension of montmorillonite K10, loaded with anaminosulfonic acid, in NMP is then added. Herein, the sulfonic acidgroups are present on the surface, whereas the amino groups are in thecavities of the montmorillonite. The composition of the suspension isagain chosen for a solid content to be between 2 and 20 weight of thepolymer content. It depends on the application for which the membrane isused. The suspension is processed to a membrane, as above. The solventis evaporated in a drying board at a temperature between 80° C. and 150°C. The membrane is peeled off from the glass plate and cured indeionized water for 12 hours at 90° C.

3) Sulfochlorinated polysulfone and aminated polysulfone are dissolvedin THF. Then, 10 weight % of montmorillonite K10 (dried and inprotonated form) is added. The suspension is stirred, degassed andprocessed to a membrane, as above. The membrane is peeled off from theglass plate and then cured in diluted HCl at 80° C., whereby thesulfochloride group is rehydrolyzed to the sulfonic acid. Then, themembrane is again further treated with deionized water, until all thehydrochloric acid is removed from the membrane.

It has now been found that the composites relating to the invention havesurprising properties:

-   -   The composites have excellent ionic conductivities even at        temperatures far beyond 100° C. Especially, the proton        conductivities of the composites are still excellent in this        temperature range, due to, on one hand, the water storing        properties of the clay materials and, on the other hand, the        self-proton conducting properties of the clay materials. The        good proton conductivities permit the use of these composites in        membrane fuel cells in the above mentioned temperature range.    -   Due to the silicates forming cavities, the chemical, mechanical,        and thermal stability of composite membranes is significantly        increased, because the polymer molecules and the clay minerals        and zeolites, respectively, can interact with each other in the        cavities. Especially, ionomer blends containing basic polymers        and base polymer components may intercalate into the Lewis acid        cavities of the silicates, due to the interaction of the base        groups, whereby an ionic cross-linking between the acidic        silicate and the basic polymer chain is formed, which, depending        on the system, may be pH independent, contributing to an        increase in mechanical, chemical, and thermal stability, in        particular if the composite membranes are used in a strongly        acidic or alkaline medium.    -   Used in DMFC, the composite membranes relating to the invention        show a reduced methanol permeability and gas-through-diffusion        across the membrane. Therein, the methanol permeability and the        permselectivity of the membrane can be fine tuned at will by:        -   The kind of phyllosilicate/tectosilicate        -   The mass percentage of the silicate in the composite        -   Targeted incorporation of spacer molecules and bifunctional            molecules into the silicate cavities. The kind and strength            of the interaction of the spacer molecules with the permeate            molecules hereby depends on the kind of their functional            groups facing outwards and the kind of the functional groups            of the permeate molecules. For example, an aminosulfonic            acid or an amino carboxylic acid is coupled with the amine            functionality in exchange of alkali-bentonite on the            bentonite surface. The second functional group is available            for the reaction with polymers or for proton transport in            electromembrane processes.        -   The membranes according to the invention show a strongly            decreased fouling (microbial attack of the ionomer membranes            by fungi and bacteria), in comparison to conventional            ionomer membranes, and this already at a content of 2-5% of            silicate (montmorillonite) in the ionomer membrane. This            property is due to the clay minerals blended with the            composite. It has been known for long that clay minerals may            act as soil improving agent by strongly slowing down the            microbial degradation, especially by fungi. It is surprising            that this property of clay minerals is also shown in            membranes which contain clay minerals. Due to this property            of the composites according to the invention, their use in            membrane separation processes in water and waste water            applications is possible and also in any other oxidizing            environment, containing, e.g., hydroxy radicals and/or            hydrogen peroxide.        -   The catalytic properties of the silicate Lewis acids, from            which the clay minerals according to the invention are made,            can also be used in the composites according to the            invention.

EXAMPLES

1. Sulfonated polyetheretherketone (sulfonation degree 70%) is dissolvedwith 5 weight % of montmorillonite in DMAc and knife-coated to amembrane of 50 μm thickness after evaporation of the solvent. Thismembrane is put into an aqueous medium contaminated with fungi. Noattack by fungi is identified. The blank without montmorillonite isheavily colonized and attacked.

2. a) Sulfonated polysulfone in salt form and polyvinylpyridine isblended in such a ratio that the final capacity is 1 milli equivalent[H⁺] per gram of the total blend. Both polymers are dissolved in DMAcand processed to a membrane. The specific resistance of this membrane is33 ohm·cm.

-   -   b) To an identical blend as in 2a, additionally 8 weight % of        activated montmorillonite is added, and the blend obtained is        processed to a membrane as in 2a. The specific resistance is        27.7 ohm·cm.

3. Polybenzimidazole dissolved in DMAc is mixed with 10 weight % ofactivated montmorillonite and as a blank without the phyllosilicate.Either blend is processed to a membrane, and the resistances aremeasured by impedance spectroscopy. Without the phyllosilicate, theresistance is 588 ohm·cm, with the phyllosilicate, 276 ohm·cm.

We claim:
 1. An ion conducting composite comprising: a polymer having anacidic component, a basic component, or both; and a functionalizedtectosilicate, wherein the functionalized tectosilicate isfunctionalized by a hydrophobisation agent having a structure satisfyingone of general formulae I or II:

wherein (i) R₁, R₂, R₃, and R₄ independently of each other representhydrogen, a straight-chain, branched, saturated or nonsaturatedhydrocarbon radical with 1 to 40 carbon atoms, (ii) X representsphosphorus or nitrogen, (iii) Y represents oxygen or sulphur, (iv) n isan integer between 1 and 5, inclusive, and (v) Z is an anion, andwherein the amount of the polymer is from 1 to 99 weight % and theamount of tectosilicate is from 99 to 1 weight %, and wherein an acid ofthe acidic component or a base of the basic component is present in thecavities of the tectosilicate.
 2. The composite of claim 1, wherein thepolymer is provided by an ionomer selected from the group consisting of(a) a cation exchange polymer comprising a cation exchange group —SO₃H,—COOH, or —PO₃H₂, wherein the polymer can be non-cross-linked orcovalently crosslinked and the polymer backbone can be a vinyl polymer,an aryl main chain polymer, polythiazole, polypyrazole, polypyrrole,polyaniline, polythiophene or any blend of these; (b) an anion exchangepolymer comprising an anion exchange group —NR₃ ⁺, PyrH⁺, IMR⁺, PyrazR⁺,TriR⁺, or other organic basic aromatic or non-aromatic groups, wherein Ris a hydrogen, alkyl, or aryl group, wherein the polymer isnon-cross-linked or covalently crosslinked, and wherein the polymercomprises a vinyl polymer, an aryl main chain polymer, polythiazole,polypyrazole, polypyrrole, polyaniline, polythiophene, or a blendthereof; (c) a polymer containing on the polymer chain both anionexchange groups from (b) and cation exchange groups from (a), whereinthe polymer comprises a vinyl polymer, an aryl main chain polymer,polythiazole, polypyrazole, polypyrrole, polyaniline, polythiophene, ora blend thereof; or (d) a blend of (a) and (b), wherein the mixing ratiocan range from 100% of (a) to 100% of (b), wherein the blend iscovalently and ionically cross-linked, and wherein the polymer comprisesa vinyl polymer, an aryl main chain polymer, polythiazole, polypyrazole,polypyrrole, polyaniline, polythiophene, or a blend thereof.
 3. Thecomposite of claim 2, characterized in that the basic component containsimidazole, vinylimidazole, pyrrazole, oxazole, carbazole, indole,isoindole, dihydrooxazole, isooxazole, thiazole, benzothiazole,isothiazole, benzoimidazole, imidazolidine, indazole,4,5-dihydropyrazole, 1,2,3-oxadiazole, furazane, 1,2,3-thiadiazole,1,2,4-thiadiazole, 1,2,3-benzotriazole, 1,2,4-triazole, tetrazole,pyrrole, aniline, pyrrolidine, or pyrrazole groups.
 4. The composite ofclaim 2, wherein the ionomer is an ionomer blend, and wherein thetectosilicate is clinoptilolite.
 5. The composite of claim 1, wherein aprecursor of an ionomer provides the polymer, wherein the precursor isselected from the group consisting of (a) the precursor of a cationexchange polymer (a1) comprising COHal, CONR₂, or COOR groups; a cationexchange polymer (a2) comprising SO₂Hal, SO₂NR₂, or SO₂OR groups; or acation exchange polymer (a3) comprising PO₃Hal₂, PO₃ (NR₂)₂, or PO3(OR)₂groups, wherein R is a hydrogen, alkyl, or aryl group, and wherein Halis a fluorine, chlorine, bromine, or iodine atom; or (b) the precursorof an anion exchange polymer comprising —NR₂, pyridyl, imidazolyl,pyrazolyl, triazolyl, or other organic basic aromatic or non-aromaticgroups, wherein R is a hydrogen, alkyl, or aryl group, and wherein Halis a fluorine, chlorine, bromine, or iodine atom.
 6. The composite ofclaim 5, wherein the polymer comprises an acid polymer, and wherein thebackbone of the polymer comprises one or more of the following repeatunits selected from the group consisting of repeating units R₁ and R₂ inthe following, bridged by bridging units selected from the group R₅-R₈in the following: R_(aromatic) R_(bridge)


7. The composite of claim 1, wherein the tectosilicate is a zeolite. 8.The composite of claim 7, wherein the zeolite is clinoptilolite.
 9. Thecomposite of claim 1, wherein the polymer comprises a basic polymer, andwherein the backbone of the polymer comprises one or more of thefollowing repeat units either elected from the group consisting ofrepeating units R₁ and R₂ in the following, bridged by bridging unitsselected from the group R₅-R₈ in the following: R_(aromatic) R_(bridge)

or


10. The composite of claim 1, wherein the polymer comprises 1) a firstpolymer comprising an acidic group and 2) a second polymer comprising abasic group.
 11. The composite of claim 1, wherein the compositemaintains ion conduction over the temperature range of from −40° C. to200° C.
 12. The composite of claim 11 adapted to be a component of afuel cell.
 13. The composite of claim 1 adapted to be a reverse osmosisor (electro)membrane, wherein the membrane is capable of separating twoor more gases or liquids.
 14. The composite of claim 1 adapted to be acatalytic membrane or a component of a membrane reactor.
 15. Thecomposite according to claim 1, further exhibiting thermal resistance upto 400° C.
 16. The composite of claim 1, wherein R₁, R₂, R₃ or R₄carries at least a functional group.
 17. The composite of claim 1,wherein two or more of R₁, R₂, R₃ and R₄ are linked together.
 18. Thecomposite of claim 1, the polymer has a cation exchange capacity between0.1 and 12 meq/g, and an anion exchange capacity between 1 and 15 meq/g,relative to the total mass of the composite.
 19. The composite of claim1, further comprising phosphoric acid.
 20. The composite of claim 1,wherein the composite is included in a membrane process.
 21. A processfor the preparation of the composite of claim 1, comprising providing apolymer component, an acid-base component, and contacting the polymercomponent, the acid-base component, and the tectosilicate, optionallywith a solvent, at a temperature from −40° C. to 300° C.